Fancy bird; a Voorburg-Cropper Pigeon. Photo by Richard Bailey
How and why did humans domesticate animals – and what might this tell us about the future of our own species?
One day in London in 1855, during an unusually cold winter, Charles Darwin went for a walk. As he strolled along the banks of the ice-bound Thames, he noticed some pigeons foraging for food. He began to wonder about their relationship to so-called ‘fancy pigeons’, the more exotic varieties favoured by fanciers and breeders. Was there an ancestor common to the nondescript blue-grey creatures on the riverbank, and those featured on the front page of Darwin’s newspaper that day, all puffed-up chests and improbable neck-ruffs?
Darwin was a pigeon-fancier himself and raised birds at his home in Kent. Observing these creatures closely, he became convinced that the various pigeon breeds descended from a single ancestor: the rock dove, or Columba livia. His fancy pigeons all interbred freely, and it seemed unlikely that a different species corresponded to each particular characteristic, none of which lived on in the wild. If man could breed a multiplicity of forms from a single thing, Darwin thought, perhaps nature could too. Domestication, for Darwin, was a laboratory for the study of evolution.
But what, exactly, is domestication? Darwin noticed that, when it came to mammals, virtually all domesticated species shared a bundle of characteristics that their wild ancestors lacked. These included traits you might expect, such as tameness and increased sociability, but also a number of more surprising ones, such as smaller teeth, floppy ears, variable colour, shortened faces and limbs, curly tails, smaller brains, and extended juvenile behaviour. Darwin thought these features might have something to do with the hybridisation of different breeds or the better diet and gentler ‘conditions of living’ for tame animals – but he couldn’t explain how these processes would produce such a broad spectrum of attributes across so many different species.
We’re still puzzling over the hows and whys of domestication. Advances in animal genetics, both ancient and modern, coupled with new techniques in archaeology, have illuminated at least some of the mechanisms behind this previously hidden transition. It’s deeply bound up with the origins of the so-called ‘Neolithic revolution’, when humans first turned to farming around 12,000 years ago. But the history of the human relationship to animals and agriculture is now being rewritten. Domestication, it appears, wasn’t a one-way street: new research suggests that species moved from wild to tame multiple times over their history, and that human agency played a far smaller role than previously believed. It’s also becoming clearer that, in the millennia we’ve spent changing animal genetics, they’ve been changing us in turn.